Excited state acid-base chemistry a new quenching mechanism

Hicks, Charles H.; Fan, Jianwei; Rutenberg, Irina; Gafney, Harry D.

doi:10.1016/s0010-8545(98)90013-3

Cited by 16 publications

(10 citation statements)

References 20 publications

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“…For both 1a and 2a deuteration of either the bipy ligands and/or the 2,5-dpp ligand leads to an increase in emission lifetime at 77 K. However in both cases the effect of deuteration of the 2,5-dpp ligand is more pronounced indicating localisation of the emissive excited 3 MLCT state on the 2,5-dpp ligand, i.e. a (p* 2,5-dpp ←d t2g ) 3 MLCT state (vide infra).…”

Section: Electronic Propertiesmentioning

confidence: 95%

“…The emission lifetime data at room temperature in aerated acetonitrile are in agreement with lifetime data reported by Balzani and coworkers. As discussed above selective ligand deuteration can provide an indication of localisation of the emitting state and the involvement of 3 MLCT states based on other ligands in the deactivation of the excited state. For example, for complexes of the type [Ru(L 1 ) 2 (L 2 )] 2+ where the ligand L 2 is deuterated, the lifetime of the emitting state will be longer only when the emitting state is based on the L 2 ligand, to a first approximation.…”

Section: Electronic Propertiesmentioning

confidence: 99%

“…Transient resonance Raman (TR 2 ) spectroscopy TR 2 spectroscopy using the single colour pump/probe method was employed at 355 nm to identify whether or not the bipy anion radical 25 (and hence a bipy based 3 MLCT state) was formed upon photoexcitation of the mono-and dinuclear complexes. Overall the TR 2 spectra obtained using pulsed excitation were identical to those obtained using continuous wave excitation at 355 nm as expected considering the strong ground state absorption of both 1a and 2a at 355 nm (Fig.…”

Section: Resonance Raman (Rr) Spectroscopy Of 1a-d and 2a-dmentioning

confidence: 99%

“…Here, we report the characterisation of the complexes [Ru(bipy) 2 ( 1). The goal of the study is two fold: firstly to determine the orbital parentage of visible and near-UV absorption bands and the localisation of the lowest 3 MLCT excited state and secondly to explore the potential of resonance Raman spectroscopy as a tool in mechanistic studies in photocatalytic dihydrogen production in heterobimetallic catalysts based on the 2,5-dpp bridging ligand such as [Ru(bipy) 2 dppPtCl 2 ] 2+ . In these studies deuteration is a key asset in simplifying the interpretation of 1 H-NMR spectra and in definitive assignment of vibrational modes observed by Raman spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

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Reinvestigating 2,5-di(pyridin-2-yl)pyrazine ruthenium complexes: selective deuteration and Raman spectroscopy as tools to probe ground and excited-state electronic structure in homo- and heterobimetallic complexes

et al. 2011

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The mono- (1) and dinuclear (2) ruthenium(II) bis(2,2'-bipyridine) complexes of 2,5-di(pyridin-2-yl)pyrazine (2,5-dpp), for which the UV/Vis absorption and emission as well as electrochemical properties have been described earlier, are reinvestigated here by resonance, surface enhanced and transient resonance Raman spectroscopy together with selective deuteration to determine the location of the lowest lying excited metal to ligand charge transfer ((3)MLCT) states. The ground state absorption spectrum of both the mono- and dinuclear complexes are characterised by resonance Raman spectroscopy. The effect of deuteration on emission lifetimes together with the absence of characteristic bipy anion radical modes in the transient Raman spectra for both the mono- and dinuclear complexes bridged by the 2,5-dpp ligand confirms that the excited state is 2,5-dpp based; however DFT calculations and the effect of deuteration on emission lifetimes indicate that the bipy based MLCT states contribute to excited state deactivation. Resonance Raman and surface enhanced Raman spectroscopic (SERS) data for 1 and 2 are compared with that of the heterobimetallic complexes [Ru(bipy)(2)(2,5-dpp)PdCl(2)](2+)3 and [Ru(bipy)(2)(2,5-dpp)PtCl(2)](2+)4. The SERS data for 1 indicates that a heterobimetallic Ru-Au complex forms in situ upon addition of 1 to a gold colloid.

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Section: Electronic Propertiesmentioning

confidence: 95%

Section: Electronic Propertiesmentioning

confidence: 99%

Section: Resonance Raman (Rr) Spectroscopy Of 1a-d and 2a-dmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Reinvestigating 2,5-di(pyridin-2-yl)pyrazine ruthenium complexes: selective deuteration and Raman spectroscopy as tools to probe ground and excited-state electronic structure in homo- and heterobimetallic complexes

et al. 2011

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“…Tris complexes of ruthenium(II) showing intense absorptions in the visible region have always been of significant interest with regard to their photophysical and photochemical properties. [38][39][40][41][42][43][44] We have checked the luminescence property of HNEt 3 [Ru(L) 3 ] in acetonitrile solution at ambient temperature (298 K) using an excitation wavelenth of 300 nm, and this complex really shows emission in the visible region with two maxima at 652 and 720 nm. Further studies on the photochemical properties of [Ru II (L) 3 ]are in progress.…”

Section: Resultsmentioning

confidence: 99%

Tris 1-Nitroso-2-naphtholate Complex of Ruthenium(II): An Efficient Building Unit for Polynuclear Complexes

et al. 1999

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Experimental SectionMaterials. Commercial ruthenium trichloride was purchased from Arora Matthey, Calcutta, India, and was converted to RuCl3‚3H2O by repeated evaporation with concentrated hydrochloric acid. 1-Nitroso-2-naphthol was purchased from Loba-Chemie, Mumbai, India. Nickel perchlorate (Ni(ClO4)2‚6H2O) was prepared by treating NiCO3 with 70% perchloric acid. Purification of acetonitrile and preparation of tetraethylammonium perchlorate (TEAP) for electrochemical work were performed as before. 20 Preparation of HNEt3[Ru(L)3]. To a solution of RuCl3‚3H2O (100 mg, 0.10 mmol) in ethanol (40 cm 3 ) was added HL (211 mg, 0.32 mmol) followed by NEt3 (123 mg, 1.23 mmol). The solution was then refluxed for 2 h. A blue precipitate started to separate during reflux. After cooling of the solution to room temperature, the precipitate was collected by filtration, washed thoroughly with water, and dried in vacuo over P4O10. Recrystallization of the crude product from 1:2 acetonitrilebenzene solution gave HNEt3[Ru(L)3] as a blue crystalline solid.

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Artificial Enzyme Catalysis Controlled and Driven by Light

Knör

2008

Chemistry A European J

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Bio-inspired chemistry based on photoresponsive molecules is a rapidly developing new strategy to mimic the function of various biological systems. The interaction of electromagnetic radiation with molecular systems is ideally suited for the control and powering of dynamic processes at the speed of light. Besides typical applications in artificial photosynthesis, many other aspects, such as the catalytic turnover of substrates or the controlled release or uptake of small bioactive molecules, are readily verified with light-driven model systems. The potential of this novel approach in biomimetic chemistry is briefly explored in this concept article.

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Excited state acid-base chemistry a new quenching mechanism

Cited by 16 publications

References 20 publications

Reinvestigating 2,5-di(pyridin-2-yl)pyrazine ruthenium complexes: selective deuteration and Raman spectroscopy as tools to probe ground and excited-state electronic structure in homo- and heterobimetallic complexes

Reinvestigating 2,5-di(pyridin-2-yl)pyrazine ruthenium complexes: selective deuteration and Raman spectroscopy as tools to probe ground and excited-state electronic structure in homo- and heterobimetallic complexes

Tris 1-Nitroso-2-naphtholate Complex of Ruthenium(II): An Efficient Building Unit for Polynuclear Complexes

Artificial Enzyme Catalysis Controlled and Driven by Light

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